#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/i2c.h>
+#include <linux/seq_file.h>
#include <drm/drm_dp_helper.h>
-#include <drm/drm_dp_aux_dev.h>
#include <drm/drmP.h>
+#include "drm_crtc_helper_internal.h"
+
/**
* DOC: dp helpers
*
err = ret;
}
- DRM_DEBUG_KMS("too many retries, giving up\n");
+ DRM_DEBUG_KMS("Too many retries, giving up. First error: %d\n", err);
ret = err;
unlock:
}
EXPORT_SYMBOL(drm_dp_link_configure);
+/**
+ * drm_dp_downstream_max_clock() - extract branch device max
+ * pixel rate for legacy VGA
+ * converter or max TMDS clock
+ * rate for others
+ * @dpcd: DisplayPort configuration data
+ * @port_cap: port capabilities
+ *
+ * Returns max clock in kHz on success or 0 if max clock not defined
+ */
+int drm_dp_downstream_max_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4])
+{
+ int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
+ bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+ DP_DETAILED_CAP_INFO_AVAILABLE;
+
+ if (!detailed_cap_info)
+ return 0;
+
+ switch (type) {
+ case DP_DS_PORT_TYPE_VGA:
+ return port_cap[1] * 8 * 1000;
+ case DP_DS_PORT_TYPE_DVI:
+ case DP_DS_PORT_TYPE_HDMI:
+ case DP_DS_PORT_TYPE_DP_DUALMODE:
+ return port_cap[1] * 2500;
+ default:
+ return 0;
+ }
+}
+EXPORT_SYMBOL(drm_dp_downstream_max_clock);
+
+/**
+ * drm_dp_downstream_max_bpc() - extract branch device max
+ * bits per component
+ * @dpcd: DisplayPort configuration data
+ * @port_cap: port capabilities
+ *
+ * Returns max bpc on success or 0 if max bpc not defined
+ */
+int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4])
+{
+ int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
+ bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+ DP_DETAILED_CAP_INFO_AVAILABLE;
+ int bpc;
+
+ if (!detailed_cap_info)
+ return 0;
+
+ switch (type) {
+ case DP_DS_PORT_TYPE_VGA:
+ case DP_DS_PORT_TYPE_DVI:
+ case DP_DS_PORT_TYPE_HDMI:
+ case DP_DS_PORT_TYPE_DP_DUALMODE:
+ bpc = port_cap[2] & DP_DS_MAX_BPC_MASK;
+
+ switch (bpc) {
+ case DP_DS_8BPC:
+ return 8;
+ case DP_DS_10BPC:
+ return 10;
+ case DP_DS_12BPC:
+ return 12;
+ case DP_DS_16BPC:
+ return 16;
+ }
+ default:
+ return 0;
+ }
+}
+EXPORT_SYMBOL(drm_dp_downstream_max_bpc);
+
+/**
+ * drm_dp_downstream_id() - identify branch device
+ * @aux: DisplayPort AUX channel
+ * @id: DisplayPort branch device id
+ *
+ * Returns branch device id on success or NULL on failure
+ */
+int drm_dp_downstream_id(struct drm_dp_aux *aux, char id[6])
+{
+ return drm_dp_dpcd_read(aux, DP_BRANCH_ID, id, 6);
+}
+EXPORT_SYMBOL(drm_dp_downstream_id);
+
+/**
+ * drm_dp_downstream_debug() - debug DP branch devices
+ * @m: pointer for debugfs file
+ * @dpcd: DisplayPort configuration data
+ * @port_cap: port capabilities
+ * @aux: DisplayPort AUX channel
+ *
+ */
+void drm_dp_downstream_debug(struct seq_file *m,
+ const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4], struct drm_dp_aux *aux)
+{
+ bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+ DP_DETAILED_CAP_INFO_AVAILABLE;
+ int clk;
+ int bpc;
+ char id[6];
+ int len;
+ uint8_t rev[2];
+ int type = port_cap[0] & DP_DS_PORT_TYPE_MASK;
+ bool branch_device = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
+ DP_DWN_STRM_PORT_PRESENT;
+
+ seq_printf(m, "\tDP branch device present: %s\n",
+ branch_device ? "yes" : "no");
+
+ if (!branch_device)
+ return;
+
+ switch (type) {
+ case DP_DS_PORT_TYPE_DP:
+ seq_puts(m, "\t\tType: DisplayPort\n");
+ break;
+ case DP_DS_PORT_TYPE_VGA:
+ seq_puts(m, "\t\tType: VGA\n");
+ break;
+ case DP_DS_PORT_TYPE_DVI:
+ seq_puts(m, "\t\tType: DVI\n");
+ break;
+ case DP_DS_PORT_TYPE_HDMI:
+ seq_puts(m, "\t\tType: HDMI\n");
+ break;
+ case DP_DS_PORT_TYPE_NON_EDID:
+ seq_puts(m, "\t\tType: others without EDID support\n");
+ break;
+ case DP_DS_PORT_TYPE_DP_DUALMODE:
+ seq_puts(m, "\t\tType: DP++\n");
+ break;
+ case DP_DS_PORT_TYPE_WIRELESS:
+ seq_puts(m, "\t\tType: Wireless\n");
+ break;
+ default:
+ seq_puts(m, "\t\tType: N/A\n");
+ }
+
+ drm_dp_downstream_id(aux, id);
+ seq_printf(m, "\t\tID: %s\n", id);
+
+ len = drm_dp_dpcd_read(aux, DP_BRANCH_HW_REV, &rev[0], 1);
+ if (len > 0)
+ seq_printf(m, "\t\tHW: %d.%d\n",
+ (rev[0] & 0xf0) >> 4, rev[0] & 0xf);
+
+ len = drm_dp_dpcd_read(aux, DP_BRANCH_SW_REV, &rev, 2);
+ if (len > 0)
+ seq_printf(m, "\t\tSW: %d.%d\n", rev[0], rev[1]);
+
+ if (detailed_cap_info) {
+ clk = drm_dp_downstream_max_clock(dpcd, port_cap);
+
+ if (clk > 0) {
+ if (type == DP_DS_PORT_TYPE_VGA)
+ seq_printf(m, "\t\tMax dot clock: %d kHz\n", clk);
+ else
+ seq_printf(m, "\t\tMax TMDS clock: %d kHz\n", clk);
+ }
+
+ bpc = drm_dp_downstream_max_bpc(dpcd, port_cap);
+
+ if (bpc > 0)
+ seq_printf(m, "\t\tMax bpc: %d\n", bpc);
+ }
+}
+EXPORT_SYMBOL(drm_dp_downstream_debug);
+
/*
* I2C-over-AUX implementation
*/
if (ret == -EBUSY)
continue;
- DRM_DEBUG_KMS("transaction failed: %d\n", ret);
+ /*
+ * While timeouts can be errors, they're usually normal
+ * behavior (for instance, when a driver tries to
+ * communicate with a non-existant DisplayPort device).
+ * Avoid spamming the kernel log with timeout errors.
+ */
+ if (ret == -ETIMEDOUT)
+ DRM_DEBUG_KMS_RATELIMITED("transaction timed out\n");
+ else
+ DRM_DEBUG_KMS("transaction failed: %d\n", ret);
+
return ret;
}
projects / cascardo / linux.git / blobdiff